The field of the invention is drywall finishing tools, specifically, tools for applying coating mud compound to corner beads.
Drywall finishing is done using a system of taping with push tools. A flat coating box is used to finish joints between two pieces of drywall by applying a mud compound. The mud compound is filled into a slot in the front of the flat box using a hand pump. The person doing the drywall finishing applies the mud by pushing on a flap to which a handle is connected in order to push the mud out. The flat coating boxes come in three sizes (seven, ten, and twelve inches) because the first coat of mud applied is thinner, then the next coat is wider, different size boxes being used to apply each coat. For sideways motion or use on a ceiling, a pole is used in conjunction with the box, the pole being attached to the back flap by wing nuts.
A corner bead is a piece of metal or paper that fastens to the outside of two pieces of unfinished sheetrock. Corner beads pose a particular problem in drywall finishing. At present, the only mechanized way of finishing corner beads is a pneumatic taping system, for example, the system manufactured by Apla-Tech, Inc., Appleton, Wis., which uses “bead tabs”. Pneumatic taping systems are expensive and therefore not widely used. Corner beads are usually finished by hand, which is a time-consuming and laborious process.